The Electoral Commission will investigate the first police commissioner elections after the polls were marred by a record-low turnout.

The watchdog's chair Jenny Watson said the dismal turnout was "a concern for everyone who cares about democracy" and said a "thorough review" would report its findings to Parliament early next year.

Although only one in seven went to the ballot box, David Cameron and Conservative ministers defended the flagship policing reform, denying the role lacked a popular mandate.

Mr Cameron - who faced criticism from electoral reform campaigners, opposition parties and one of his own backbenchers - argued public interest would rise once the commissioners began work.

Conservatives won 16 commissioner posts, Labour 13 and Independents 12 in the elections across England and Wales.

The highest-profile casualty was Labour former deputy prime minister Lord Prescott, who lost out to his Tory rival in Humberside.

Prescott lost out to his Tory rival in Humberside

Lord Prescott led after the first round of votes but when second preference votes were totted up in Bridlington the 74-year-old was overtaken by Tory local businessman and councillor Matthew Grove.

Lord Prescott said: "Don't let it take away from the fact that I have reduced a 30,000 Tory majority in this area to 2,000."

In some cities barely more than 10% voted - with one polling station in Newport, Gwent seeing no-one attend all day.

There were also reported to be very high numbers of spoiled ballots among those who did turn out.

Shadow home secretary Yvette Cooper said spending up to £100m on the largely-ignored elections had been "bad for policing, bad for democracy and bad for taxpayers".

And Liberal Democrat president Tim Farron warned that commissioners - who will have powers to set force priorities and budgets as well as to hire and fire chief constables - would struggle to claim a mandate.

Complaints have centred on the Government's alleged failure to give the public enough information about the new role and the candidates - coupled with the poll being held in November's dark and cold conditions.

Ms Watson said: "These were new elections taking place at an unfamiliar time of year, which is why we have made clear at every stage that it would be important to engage effectively with voters.

"The Government took a number of decisions about how to run these elections that we did not agree with."

Mr Grove, who beat Lord Prescott to become the new police commissioner, said: "The public didn't have a good understanding of this function, of this role.

"I believe that very much lies at the door of the national media who have almost run a campaign to encourage people to boycott it.

"Well my role for the next three-and-a-half years is to demonstrate that actually I can do a good job for the people of this area. I will serve them, I will make this area safer, I will reduce crime and I think we will see significantly higher turnouts next time round."